In 2010, approximately 250,000 women developed invasive or in-situ breast cancer in the United States. The majority of those women sought medical treatment for their disease. Women diagnosed with early stage breast cancer have several options for treatment. The surgical options include mastectomy, with or without reconstruction, or lumpectomy followed by radiation therapy and possibly chemotherapy.
Women choosing lumpectomy and radiation therapy undergo breast-conserving surgery followed by approximately three to six weeks of radiation therapy. The radiation is intended to kill any tumor cells remaining in the breast after surgical removal of the primary tumor. A specialist physician (i.e., radiation oncologist) works in conjunction with a team of physicists, dosimetrists, and radiation-therapy-machine operators (“therapists”) to plan and deliver the radiation treatment.
It is particularly important that radiation is delivered to the affected tissue (1) precisely and (2) in reproducible fashion. In particular, the high-energy photons must be delivered to the same planned volume of tissue—the “target”—each session. Care must be taken to avoid irradiating tissues surrounding the target, most importantly lung and heart tissue. Since multiple radiation treatment sessions are required, a reproducible set-up is necessary to ensure that the target site receives the intended cumulative dose of radiation. Receiving the full cumulative dose reduces the patient's risk of developing a local recurrence of the cancer in the treated breast or metastatic spread of the disease.
As such, the best outcomes are achieved when (a) precise radiation treatment parameters are followed, (b) a favorable breast geometry is attained, and (c) a reproducible set-up is established. Satisfying requirements (b) and even more so, (c), can be challenging, as discussed further below.
A woman's breast geometry will change somewhat each time she is on the treatment table. That is, particularly for a large-breasted woman, the shape of the breast is altered as a function of how the breast lies on her chest (e.g., falling off to the side, lying flat, etc.). This complicates the ability to precisely reproduce, during actual treatment, the position/geometry of the breast during the original radiation-planning scan. As a consequence, during an actual treatment, the treatment machine—a very valuable resource—must be idled while time is spent adjusting the patient's position on the treatment table to try, with varying success, to reproduce the original breast geometry and position.
The majority of patients are treated in a supine position with the arm on the affected side “chicken-winged” out of the radiation field over their head. The affected breast can therefore be isolated and treated. The ideal breast geometry for treatment is akin to a tight compact breast mound with no folds of skin.
Women with large, pendulous, ptotic breasts pose challenges for the radiation oncology team. Because of the anatomical shape of the treatment volume and frequent dose variations, acute skin toxicity occurs in “hot spots” such as the axillary tail and the inframammary folds. In addition, breast overhang both in the inferior and/or lateral directions often requires enlargement of the radiation field, which disadvantageously captures larger areas of normal tissue in the radiation tangential fields. Dry and moist desquamation (i.e., raw, peeling areas of skin) can develop in hot spots and in areas where tissue folds upon itself. These problems can necessitate treatment breaks until the skin recovers. These treatment breaks compromise the efficacy of the radiation in killing cancer cells. Furthermore, if a large, pendulous breast falls superiorly, physicians may need to use an inclined breast board (wedged board) to shift the breast. This board must be moved on and off the treatment table before and after each treatment session.
Another treatment strategy for large-breasted women is to place them in the lateral decubitus position with a wedge. Yet a further approach is to have the patient in a prone position wherein their ptotic breast hangs through a “breast board.” For many patients, this is a difficult position to achieve and maintain. More importantly, when a patient is in this position, there can be a tradeoff in terms of adequate treatment of the chest wall. Elderly and obese women find the prone set-up position difficult for other health reasons. Additionally, polyvinyl rings are sometimes strapped to large breasts to attain a desired geometry, but it is not possible to reliably reproduce such a set-up. All of these alternative strategies/approaches/positions consume valuable time on the treatment table.
Women with widely spaced, large, pendulous breasts also pose challenges for homogenous treatment. Often, higher-energy radiation is required to achieve homogeneity. Unfortunately, many radiation centers do not have dual-energy machines. Moreover, the higher-energy radiation results in a higher skin dose, which often causes increased skin reaction.
Currently, immobilization devices for women on the treatment table include cradles, plastic molds and netting. There are drawbacks to all such forms of immobilization. Simply put, exact, reproducible, comfortable set-up devices do not exist.
With current treatment regimens, a patient is completely exposed from the waist up while receiving treatment. For many women, this loss of privacy adds to feelings of exposure and vulnerability.